Update python-dateutil from 2.6.1 to 2.7.0 (#3330)

requirements/common.txt

@@ -168,9 +168,9 @@ hawkrest==1.0.0 \
     --hash=sha256:a3b9c52ee86b0e437aa16819356e57ea79706e58b52ffa4cb908a02d1ebd4875 \
     --hash=sha256:47d0878352bc0491534da6df7be1fd2f18a515ab4ea55c0c943056b21f286132
 
-python-dateutil==2.6.1 \
-    --hash=sha256:95511bae634d69bc7329ba55e646499a842bc4ec342ad54a8cdb65645a0aad3c \
-    --hash=sha256:891c38b2a02f5bb1be3e4793866c8df49c7d19baabf9c1bad62547e0b4866aca
+python-dateutil==2.7.0 \
+    --hash=sha256:07009062406cffd554a9b4135cd2ff167c9bf6b7aac61fe946c93e69fad1bbd8 \
+    --hash=sha256:8f95bb7e6edbb2456a51a1fb58c8dca942024b4f5844cae62c90aa88afe6e300
 
 requests-hawk==1.0.0 --hash=sha256:c2626ab31ebef0c81b97781c44c2275bfcc6d8e8520fc4ced495f0f386f8fe26